Thesis (M. Tech.) -- Central University of Technology, Free State, 2008 / Motivated by the challenges associated with demonstrating the cervicothoracic junction, a study was conducted at Pelonomi Regional Hospital from May 2006 to June 2007. In this study, two projections of the cervicothoracic junction were done, with the only difference between them being the orientation of the arms. One projection was done using the swimmer’s projection and the other using an adaptation of the swimmer’s projection where the orientation of the arms was reversed. The sample, consisting of 45 patients, was referred from the emergency department and wards. Most of the patients (95.5%) were examined using a computed radiography system providing digital images that were printed using a laser film printer. Other patients were examined using conventional film/screen systems. The objectives of this study were to compare the two imaging techniques with reference to diagnostic quality of the projections, diagnosis of pathology and repeat rate. Radiographers obtained the two projections of the cervical spine; the researcher collected the images and distributed these to three participating radiologists on a rotational basis. The radiologists evaluated the films using a set of criteria; a biostatistician analysed the results of these evaluations. In all the criteria of image quality the swimmer’s projection showed better results. There were also, however, instances where the adapted swimmer’s had better results. The differences in percentages were not significant enough to show any statistical difference between the resultant images of the two techniques. No valid deduction could be made in relation to the demonstration of pathology due to variable instances of pathology evaluated by the radiologists. The repeat rate of the adapted swimmer’s projection compared well with the swimmer’s projection. Though the swimmer’s projection had better results for most of the criteria used in this study, no unequivocal, statistically significant evidence of it demonstrating C7-T1 better could be found. What was evident was the validity of the adapted swimmer’s projection as an alternative under certain conditions. Knowing that there is an alternative method to visualising the C7- T1 junction could be beneficial not only to radiography, but also to our patients. In cases where the swimmer’s projection is not possible due to extremity injuries, an alternative arm orientation can be useful. The alternative can also address the problem regarding multiple repeats of the swimmer’s projection.

Thesis (M.Tech.: Radiography) - Dept. of Radiography, Durban University of Technology, 2006 xxiv, 214 leaves, Annexures A-L / The aim of this research was to determine normal bone mineral density (BMD) reference ranges (means and standard deviations) for the lumbar spine, total hip and distal forearm, for Indian women of varying age groups in KwaZulu-Natal. The aim also included a comparison of the study population reference ranges with those provided by the manufacturer in order to evaluate any diagnostic implications.

A dissertation submitted in full compliance with the requirements for the M.Tech: Radiography,Durban University of Technology, 2006. / The aim of this research was to determine normal bone mineral density (BMD) reference ranges (means and standard deviations) for the lumbar spine, total hip and distal forearm, for Indian women of varying age groups in KwaZulu-Natal. The aim also included a comparison of the study population reference ranges with those provided by the manufacturer in order to evaluate any diagnostic implications. / M

Submitted in compliance with the requirement for Degree of Doctor of Technology: Radiography, Durban University of Technology, 2013. / The shortage of radiologists in Zambia has persistently made the provision of equitable access to optimum radiological services unattainable in the current radiological service delivery system, while equity in distribution of cost-effective and quality healthcare service as closer to the community as possible is at the core of Zambia’s vision in the National Health Strategic Plan. This vision is maintained in Zambia’s Sixth National Development Plan, for the period 2011 to 2015. The number of radiologists as low as three radiologists, for a population of thirteen million people, makes the possibility of ever providing optimum radiological services equitably accessible to the community unattainable, without launching and upholding a precise remedial intervention. The purpose of the study was to develop a framework for sustainable radiographic human capital developmental guidelines embracing advanced radiographic practice and optimum radiological services, with special focus on hospitals without radiologists. The objectives were to: a) analyse the existing radiographic services and/or practices in rural Zambian hospitals without radiologists; b) examine the views of radiographers, physicians, and patients in hospitals without radiologists, regarding adequacy of radiological service delivery; (c) determine desirable competencies for frontline radiographers in comprehensive radiological service delivery, as well as the benefits of such competencies to the community and the health service facilities; d) analyse the healthcare managements’ expectations regarding frontline radiographers’ capabilities in rendering comprehensive radiological services in healthcare settings without the radiologists, e) formulate, implement, and evaluate a training programme for radiographers for comprehensive radiological services; with specific references to client (physician and patient) satisfaction and radiographic competencies; and (f) develop a framework for human capital development for frontline radiographers in providing comprehensive radiological services. The Accenture Human Capital Development Framework (AHCDF) was employed as the theoretical framework to link all key aspects of the inquiry (Thomas, Cheese and Benton, 2003). An Action Research design was used involving multidisciplinary participation, including patients, in the five cyclical phases of the Action Research design; diagnosing, planning, acting, evaluating, and specifying learning. The route of knowledge generation and application was guided by retroductive or abductive cyclical logical process. The interviews, document analysis, and questionnaires were applied to obtain data, whereas a designed training programme for frontline radiographers was piloted and evaluated within this study. The study’s data management and analysis were largely by qualitative methods, though quantitative aspects involving percentages as in descriptive statistics were also involved where appropriate. The discussion, integrates the research findings under appropriate themes of the theoretical framework. An investment perspective in AHCDF is linked to ways of investing in radiographers’ education and training towards extended roles is discussed. The radiographers’ extended roles are seen as a catalyst to desirable radiological technology, radiological service designs, and corresponding radiological service outcome. The benefit of this proposed investment is seen as promoting equitable access to radiological services, with averted or reduced costs ascribed to referrals of patients among hospitals. Consequently, incomes of households and healthcare institutions would be preserved for poverty reduction by reduced referral-related costs. The researcher-devised frontline radiographic human capital developmental (FRHCD) conceptual framework is developed and a way forward recommended. / African Doctoral Dissertation Research Fellowship International Development Research Center (IDRC) Ford Foundation

Thesis (D.Tech.: Radiography)-Dept. of Radiography, Durban Institute of Technology, 2006 xxiii, 166 leaves / The purpose of this study was to evaluate 99mTc- methoxyisobutylisonitrile (MIBI) imaging, in terms of sensitivity and specificity, for non invasively detecting extracutaneous involvement of Kaposi’s sarcoma (KS) and for differentiating pulmonary infection from malignancy in acquired immunodeficiency syndrome (AIDS) patients before and after treatment. Current investigations are invasive.

This thesis investigates the exact minimisation of treatment delivery time for Intensity Modulated Radiation Therapy (IMRT) for the treatment of cancer using Multileaf Collimators (MLC). Although patients are required to remain stationary during the delivery of IMRT, inevitably some patient movement will occur, particularly if treatment times are longer than necessary. Therefore minimising the treatment delivery time of IMRT may result in less patient movement, less inaccuracy in the dosage received and a potentially improved outcome for the patient. When IMRT is delivered using multileaf collimators in 'step and shoot' mode, it consists of a sequence of multileaf collimator configurations, or shape matrices; for each, time is needed to set up the configuration, and in addition the patient is exposed to radiation for a specified time, or beam-on time. The 'step and shoot leaf sequencing' problems for minimising treatment time considered in this thesis are the constant set-up time Total Treatment Time (TTT) problem and the Beam-on Time Constrained Minimum Cardinality (BTCMC) problem. The TTT problem minimises a weighted sum of total beam-on time and total number of shape matrices used, whereas the BTCMC problem lexicographically minimises the total beam-on time then the number of shape matrices used in a solution. The vast majority of approaches to these strongly NP-hard problems are heuristics; of the few exact approaches, the formulations either have excessive computation times or their solution methods do not easily incorporate multileaf collimator mechanical constraints (which are present in most currently used MLC systems). In this thesis, new exact mixed integer and integer programming formulations for solving the TTT and BTCMC problems are developed. The models and solution methods considered can be applied to the unconstrained and constrained versions of the problems, where 'constrained' refers to the modelling of additional MLC mechanical constraints. Within the context of integer programming formulations, new and existing methods for improving the computational efficiency of the models presented are investigated. Numerical results for all variations considered are provided. This thesis demonstrates that significant computational improvement can be achieved for the exact mixed integer and integer programming models investigated, via solution approaches based on an idea of systematically 'stepping-up' through the number of shape matrices used in a formulation, via additional constraints (particularly symmetry breaking constraints) and via the application of improved bounds on variables. This thesis also makes a contribution to the wider field of integer programming through the examination of an interesting substructure of an exact integer programming model. In summary, this thesis presents a thorough analysis of possible integer programming models for the strongly NP-hard 'step and shoot' leaf sequencing problems and investigates and applies methods for improving the computational efficiency of such formulations. In this way, this thesis contributes to the field of leaf sequencing for the application of Intensity Modulated Radiation Therapy using Multileaf Collimators.

Thesis (D.Tech.: Radiography)-Dept. of Radiography, Durban Institute of Technology, 2006 xxiii, 166 leaves / The purpose of this study was to evaluate 99mTc- methoxyisobutylisonitrile (MIBI) imaging, in terms of sensitivity and specificity, for non invasively detecting extracutaneous involvement of Kaposi’s sarcoma (KS) and for differentiating pulmonary infection from malignancy in acquired immunodeficiency syndrome (AIDS) patients before and after treatment. Current investigations are invasive.

Thesis (MScEng (Applied Mathematics))--University of Stellenbosch, 2006. / This thesis investigates the various components required for the development of a patient position verification system to replace the existing system used by the proton facilities of iThemba LABS1. The existing system is based on the visual comparison of a portal radiograph (PR) of the patient in the current treatment position and a digitally reconstructed radiograph (DRR) of the patient in the correct treatment position. This system is not only of limited accuracy, but labour intensive and time-consuming. Inaccuracies in patient position are detrimental to the effectiveness of proton therapy, and elongated treatment times add to patient trauma. A new system is needed that is accurate, fast, robust and automatic. Automatic verification is achieved by using image registration techniques to compare the PR and DRRs. The registration process finds a rigid body transformation which estimates the difference between the current position and the correct position by minimizing the measure which compares the two images. The image registration process therefore consists of four main components: the DRR, the PR, the measure for comparing the two images and the minimization method. The ray-tracing algorithm by Jacobs was implemented to generate the DRRs, with the option to use X-ray attenuation calibration curves and beam hardening correction curves to generate DRRs that approximate the PRs acquired with iThemba LABS’s digital portal radiographic system (DPRS) better. Investigations were performed mostly on simulated PRs generated from DRRs, but also on real PRs acquired with iThemba LABS’s DPRS. The use of the Correlation Coefficient (CC) and Mutual Information (MI) similarity measures to compare the two images was investigated. Similarity curves were constructed using simulated PRs to investigate how the various components of the registration process influence the performance. These included the use of the appropriate XACC and BHCC, the sizes of the DRRs and the PRs, the slice thickness of the CT data, the amount of noise contained by the PR and the focal spot size of the DPRS’s X-ray tube. It was found that the Mutual Information similarity measure used to compare 10242 pixel PRs with 2562 pixel DRRs interpolated to 10242 pixels performed the best. It was also found that the CT data with the smallest slice thickness available should be used. If only CT data with thick slices is available, the CT data should be interpolated to have thinner slices. Five minimization algorithms were implemented and investigated. It was found that the unit vector direction set minimization method can be used to register the simulated PRs robustly and very accurately in a respectable amount of time. Investigations with limited real PRs showed that the behaviour of the registration process is not significantly different than for simulated PRs.

Le but de notre travail a été d’évaluer l’effet de la réduction de la dose d’irradiation en TDM multibarrette quant à la performance diagnostique, la confiance de l’observateur dans le diagnostic proposé, la capacité à suggérer un diagnostic alternatif dans quelques pathologies courantes et/ou caractérisées par des situations de faibles contrastes entre les structures anatomiques normales ou pathologiques. Nous avons donc comparé ces paramètres entre des TDM à doses réduites et à doses standard telles que couramment rapportées dans la littérature dans les circonstances suivantes :<p><p>•\ / Doctorat en sciences médicales / info:eu-repo/semantics/nonPublished

The focus of this study was on the problem of unwarranted demand for radiological imaging by patients in rural KZN of South Africa. Literature in the context of this topic is scarce. Consequently the aim of this study was to describe sociodemographic factors that might influence patients demand for x-ray examinations. A quantitative in the form of a cross sectional survey was done. A convenient sample of 110 patients was surveyed using a structured questionnaire. Results of the study indicate that age, and educational level might influence patients’ demand for x-ray examinations. The study also revealed that very few respondents 10.9% (n=12) had knowledge about x-rays. The study further revealed that there might be other factors such as patients’ perceived benefits of x-rays, beliefs, lack of public health awareness as well as lack of effective communication between patients and health care providers. / Health Studies / M.A. (Public Health)